A human abuse-potential study found placebo-like drug liking at the lowest sunobinop dose, while higher doses produced a different profile and some performance effects remained at the low dose.
Harris and colleagues studied sunobinop, a partial nociceptin receptor agonist, in healthy adults with a history of nonmedical use of sedating central nervous system drugs. Triazolam served as the positive control. Fifty participants completed the randomized, double-blind, double-dummy crossover treatment phase.
Participants received sunobinop 1, 6, and 10 mg; triazolam 0.5 and 1 mg; and placebo in separate treatment periods. Before entering that phase, participants had to demonstrate that they could distinguish triazolam from placebo and show a qualifying drug-liking response. This selection strengthened the assay’s ability to detect liking but defined a specialized study population.
On the primary maximum drug-liking visual analog scale, sunobinop 1 mg was statistically equivalent to placebo under the study’s equivalence criterion and lower than the triazolam controls. That finding supported a relatively low liking signal at the dose the authors considered potentially therapeutic.
At 6 and 10 mg, sunobinop drug-liking maxima exceeded placebo and were not significantly different from triazolam. Describing the entire drug as placebo-like would therefore erase the dose-dependent finding. A nonsignificant comparison with triazolam also does not by itself prove that the treatments were equivalent.
At sunobinop 1 mg, the authors still found modest statistically significant effects on some processing-speed, response-time, vigilance, and tracking measures. Other tested domains did not differ from placebo. At higher doses, cognitive and motor effects were broadly comparable with triazolam, with differences across particular endpoints.
These results show why a low subjective liking score cannot be treated as proof of unimpaired performance. Liking, sedation, memory, and motor function are distinct outcomes even when they are measured during the same dosing session.
This was a single-dose laboratory study in selected adults, most of whom were men. It did not measure dependence during prolonged treatment, real-world misuse incidence, or driving safety. Triazolam provided evidence that the assay could detect a known sedative response; the comparison did not create an impairment threshold for either drug. The appropriate conclusion remains specific to dose, population, and endpoint.
Original analysis of the supplied journal article, identified as PMC13105734.